consolidate rpp logic in ProjectStructure

Author: a-friedman

packages/pages/src/build/build.ts

@@ -1,10 +1,6 @@
 import { Command } from "commander";
 import { build } from "vite";
 import { ProjectStructure } from "../common/src/project/structure.js";
-import {
-  applyReverseProxyOverride,
-  buildReverseProxyOverride,
-} from "../util/reverseProxyOverride.js";
 
 /**
  * The arguments passed to the build CLI command.
@@ -22,18 +18,7 @@ export interface BuildArgs {
  */
 const handler = async (buildArgs: BuildArgs) => {
   const { scope, pluginFilesizeLimit, pluginTotalFilesizeLimit, reverseProxyPrefix } = buildArgs;
-  const trimmedReverseProxyPrefix = reverseProxyPrefix?.trim();
-  const projectStructure = await ProjectStructure.init({
-    scope,
-    reverseProxyPrefix: trimmedReverseProxyPrefix || undefined,
-  });
-
-  if (projectStructure.config.reverseProxyPrefix) {
-    const reverseProxyOverride = buildReverseProxyOverride(
-      projectStructure.config.reverseProxyPrefix
-    );
-    applyReverseProxyOverride(projectStructure, reverseProxyOverride);
-  }
+  const projectStructure = await ProjectStructure.init({ scope }, reverseProxyPrefix);
 
   // Pass CLI arguments as env variables to use in vite-plugin
   if (scope) {

packages/pages/src/common/src/project/structure.test.ts

@@ -75,16 +75,30 @@ describe("ProjectStructure.init", () => {
     try {
       fs.writeFileSync(
         path.join(tempDir, "vite.config.js"),
-        'throw new Error("vite config loaded before reverse proxy override");\n'
+        'throw new Error("vite config loaded before reverse proxy override");\nexport default { build: {} };\n'
       );
+      fs.writeFileSync(path.join(tempDir, "config.yaml"), "");
       process.chdir(tempDir);
 
-      const projectStructure = await ProjectStructure.init({
+      const projectStructure = await ProjectStructure.init(
+        undefined,
+        "  www.brand.com/locations  "
+      );
+
+      expect(projectStructure.config.reverseProxyOverride).toEqual({
         reverseProxyPrefix: "www.brand.com/locations",
+        assetsDir: "locations/assets",
+        dynamicRoute: {
+          from: "/assets/*",
+          to: "/locations/assets/:splat",
+          status: 200,
+        },
       });
-
       expect(projectStructure.config.subfolders.assets).toBe("locations/assets");
-      expect(new ProjectStructure().config.reverseProxyPrefix).toBeUndefined();
+      expect(fs.readFileSync(path.join(tempDir, "vite.config.js"), "utf-8")).toContain(
+        'assetsDir: "locations/assets"'
+      );
+      expect(new ProjectStructure().config.reverseProxyOverride).toBeUndefined();
     } finally {
       fs.rmSync(tempDir, { recursive: true, force: true });
     }

packages/pages/src/common/src/project/structure.ts

@@ -2,7 +2,11 @@ import pathLib from "node:path";
 import merge from "lodash/merge.js";
 import fs from "node:fs";
 import { Path } from "./path.js";
-import { parseReverseProxyPrefix } from "../../../util/reverseProxyOverride.js";
+import {
+  applyReverseProxyOverride,
+  buildReverseProxyOverride,
+  type ReverseProxyOverride,
+} from "../../../util/reverseProxyOverride.js";
 import { determineAssetsFilepath } from "../assets/getAssetsFilepath.js";
 import { determinePublicFilepath } from "../assets/getPublicFilepath.js";
 
@@ -143,9 +147,9 @@ export interface ProjectStructureConfig {
   scope?: string;
 
   /**
-   * The reverse proxy prefix for the current build.
+   * The build configuration derived from the reverse proxy prefix.
    */
-  reverseProxyPrefix?: string;
+  reverseProxyOverride?: ReverseProxyOverride;
 }
 
 const DEFAULT_ASSETS_DIR = "assets";
@@ -221,16 +225,20 @@ export class ProjectStructure {
     this.config = mergedConfig;
   }
 
-  static init = async (projectStructureConfig?: Optional<ProjectStructureConfig>) => {
+  static init = async (
+    projectStructureConfig?: Optional<ProjectStructureConfig>,
+    reverseProxyPrefix?: string
+  ) => {
     const projectStructure = new ProjectStructure(projectStructureConfig);
     const config = projectStructure.config;
 
     const viteConfigPath = projectStructure.getViteConfigPath()?.getAbsolutePath() ?? "";
 
-    if (config.reverseProxyPrefix) {
-      const parsedReverseProxyPrefix = parseReverseProxyPrefix(config.reverseProxyPrefix);
-      config.reverseProxyPrefix = parsedReverseProxyPrefix.reverseProxyPrefix;
-      config.subfolders.assets = `${parsedReverseProxyPrefix.subpath}/assets`;
+    if (reverseProxyPrefix) {
+      const reverseProxyOverride = buildReverseProxyOverride(reverseProxyPrefix);
+      config.reverseProxyOverride = reverseProxyOverride;
+      config.subfolders.assets = reverseProxyOverride.assetsDir;
+      applyReverseProxyOverride(projectStructure);
     } else {
       // TODO: handle other extensions
       const assetsDir = await determineAssetsFilepath(DEFAULT_ASSETS_DIR, viteConfigPath);

packages/pages/src/util/reverseProxyOverride.test.ts

@@ -4,7 +4,6 @@ import path from "node:path";
 import { afterEach, describe, expect, it } from "vitest";
 import { ProjectStructure } from "../common/src/project/structure.js";
 import {
-  applyReverseProxyOverride,
   buildReverseProxyOverride,
   updateConfigYaml,
   updateViteConfig,
@@ -278,7 +277,7 @@ export default defineConfig({
   });
 });
 
-describe("applyReverseProxyOverride", () => {
+describe("ProjectStructure.init with a reverse proxy override", () => {
   const previousCwd = process.cwd();
 
   afterEach(() => {
@@ -302,12 +301,7 @@ describe("applyReverseProxyOverride", () => {
       );
       process.chdir(tempDir);
 
-      const reverseProxyOverride = buildReverseProxyOverride("www.brand.com/locations");
-      const projectStructure = await ProjectStructure.init({
-        scope: "brand",
-        reverseProxyPrefix: reverseProxyOverride.reverseProxyPrefix,
-      });
-      applyReverseProxyOverride(projectStructure, reverseProxyOverride);
+      await ProjectStructure.init({ scope: "brand" }, "www.brand.com/locations");
 
       expect(fs.readFileSync(path.join(tempDir, "brand", "config.yaml"), "utf-8")).toContain(
         "reverseProxyPrefix: www.brand.com/locations"
@@ -338,12 +332,9 @@ describe("applyReverseProxyOverride", () => {
       );
       process.chdir(tempDir);
 
-      const reverseProxyOverride = buildReverseProxyOverride("www.brand.com/locations");
-      const projectStructure = await ProjectStructure.init({
-        scope: "brand",
-        reverseProxyPrefix: reverseProxyOverride.reverseProxyPrefix,
-      });
-      expect(() => applyReverseProxyOverride(projectStructure, reverseProxyOverride)).not.toThrow();
+      await expect(
+        ProjectStructure.init({ scope: "brand" }, "www.brand.com/locations")
+      ).resolves.toBeDefined();
       expect(fs.readFileSync(path.join(tempDir, "vite.config.js"), "utf-8")).toContain(
         'assetsDir: "locations/assets"'
       );
@@ -360,14 +351,9 @@ describe("applyReverseProxyOverride", () => {
       fs.writeFileSync(path.join(tempDir, "vite.config.js"), "export default { build: {} };\n");
       process.chdir(tempDir);
 
-      const reverseProxyOverride = buildReverseProxyOverride("www.brand.com/locations");
-      const projectStructure = await ProjectStructure.init({
-        scope: "brand",
-        reverseProxyPrefix: reverseProxyOverride.reverseProxyPrefix,
-      });
-      expect(() => applyReverseProxyOverride(projectStructure, reverseProxyOverride)).toThrow(
-        /config\.yaml does not exist/
-      );
+      await expect(
+        ProjectStructure.init({ scope: "brand" }, "www.brand.com/locations")
+      ).rejects.toThrow(/config\.yaml does not exist/);
     } finally {
       fs.rmSync(tempDir, { recursive: true, force: true });
     }

packages/pages/src/util/reverseProxyOverride.ts

@@ -95,10 +95,12 @@ export const buildReverseProxyOverride = (reverseProxyPrefix: string): ReversePr
  * Updates the scoped config.yaml and vite.config.js files that the build will
  * read so the normal build pipeline picks up the reverse proxy override.
  */
-export const applyReverseProxyOverride = (
-  projectStructure: ProjectStructure,
-  reverseProxyOverride: ReverseProxyOverride
-): void => {
+export const applyReverseProxyOverride = (projectStructure: ProjectStructure): void => {
+  const reverseProxyOverride = projectStructure.config.reverseProxyOverride;
+  if (!reverseProxyOverride) {
+    throw new Error("Cannot apply reverse proxy override because none is configured.");
+  }
+
   const finisher = logger.timedLog({
     startLog: "Applying reverse proxy override",
   });